here is what i think is a good review from a user who is testing a gain master against the antron 99 & here is what the user said below,

This is my findings after testing the Sirio Gain Master against the Antron 99. Both antennas were at a similar height and were connected to a York 863. Please note that if you are going to use your Sirio Gain Master for DX purposes then it should be as mounted as close to the ground as possible for optimum results. On the other hand, if you are only use the antenna for ground wave purposes, i.e. talking to your mate 5, 10, 20 miles away then it must be mounted as high as possible and away from obstructions